Devices for warning the patient when a predetermined load is placed on his foot are known for use in situations where due to a fracture or orthopedic surgery the load on a leg must be limited. Gradisar U.S. Pat. No. 3,702,999 and Pfeiffer U.S. Pat. No. 3,791,375 each disclose such a device. The prior art devices employ a plurality of sensing devices each of which senses the load in a particular location. In an effort to sum the responses of the separate sensing units, Pfeiffer relies upon measuring flow instead of pressure. In accordance with this invention a single unitary sensing device in the form of a liquid filled tube senses the loading under the patient' s foot and eliminates the necessity for having a system for summing a plurality of loads. In addition, this invention combines accuracy with low cost and reliability. The device of the invention can be used in either foot interchangeably.